Ive got a 2002 Mack CH600 dumptruck with e7 427 engine. Randomly.....seems more often as of late it will randomly just die while going down the road. Like you turn the key off. Its not a fuel issue Im 100% sure of that. Its something electrical..ive checked and cleaned connections on solenoid, black box nxt to it, ECM plugs,, etc. Scrape/wire brush/contact cleaner. Checked all fuses, nothing has seemed to phase it. One thing that is weird is that sometimes when I go to start it of a morning it you will just hear a click, turn key off back on. Click. Third time it might start up like normal. Might be 1st time. Maybe key switch is bad or ignition......huess thats the same thing. Will randomly die at idle, sometimes all the way, sometimes just die then pick back up. Sometimes going down the road. 90% of the time you can kick it out of gear and turn key off and then recrank, pull back in gear and carry on. Alot of times it will say NO INFO on the display. Left me on the side of the road other day for two hours before it decided to crank up. ALWAYS turns over fine but wont fire. Usually stating NO INFO. Ive read about coolant getting into ecm. That doesnt seem to be an issue. Ive read about solenoid on firewall. Ive read about broken wires/fuses. Ive checked all I know to check. Any help is appreciated. I cant afford for it to be down right now.
Do u know about the relays behind the glove compartment.?? That’s where the emergency shut off relay lives.. U can swap them to see if any are loose.
I know there are relays but not sure which are which.
They are labeled. Least they are in my R model, and the CH is pretty much the same cab.
Follow the harness down the firewall. There's several P-clamps supporting the harness. Inspect the clamps where they touch the harness. I've seen where they chafe through and ground individual wires through the fabric loom. The shorts hide really well. Good luck.